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Molecular simulation study of aqueous solutions of alifatic alcohols
Peštuka, Martin ; Žídek, Jan (referee) ; Janeček, Jiří (advisor)
The aim of this bachelor thesis was to carry out set of molecular dynamic simulations of aqueous solutions of aliphatic alcohols in infinite attenuation. In order to work with molecular dynamic simulations it was necessary to become familiar with the program equipment to perform molecular dynamic simulations and analyze the results. Within the work the basic simulation boxes contained 300, 400, 500 and 1000 water molecules and one molecule of aliphatic alcohol. From the simulated trajectories we evaluated the volume change associated with the insertion of one particle of alcohol and the radial distribution functions around the molecule of solute. The results were compared with experimental data.
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Effect of metal ions on the rheological behaviour of polyelectrolyte solutions
Lišková, Kateřina ; Běťák, Jiří (referee) ; Janeček, Jiří (advisor)
This diploma thesis is focused on two parts. The first one deals with rheological behavior of sodium carboxymethylcellulose (CMC-Na) solutions in the presence of sodium and calcium ions. The solutions of various concentrations were prepared by solubilization in aqueous solutions of NaCl or CaCl2. The effect of monovalent and bivalent ions on apparent viscosity and viscoelastic properties of these solutions was studied. It was found that in the case of low concentrations of CMC-Na in the sample (up to 0.5% w/w) the elastic character increases. At the same time the stiffness of the sample is higher with higher concentration of calcium ion in the solution. This increase might indicate the formation of gel network. On the other hand the viscosity of these solutions decreases with higher concentration of calcium ions. In case of solutions with concentration higher than 1.5% w/w changes of viscosity did not happen by influence of addition ions. Rheological behavior was compared also with solutions prepared without adding an electrolyte as well as with acid form of carboxymethylcellulose (CMC-H). In terms of second part the molecular dynamic simulations of hyaluronan tetramer both sodium and calcium in aqueous medium were performed. Structure and arrangement of water molecules in the surrounding of hyaluronan chain were studied. Structure was described by formalism of radial distribution functions. In the case of system containing sodium ions only, the obtained results are in accordance with earlier published data. Presence of calcium ions does not cause qualitative changes during the radial distribution functions in comparison with the system with sodium ions.
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Effect of metal ions on the rheological behaviour of polyelectrolyte solutions
Lišková, Kateřina ; Běťák, Jiří (referee) ; Janeček, Jiří (advisor)
This diploma thesis is focused on two parts. The first one deals with rheological behavior of sodium carboxymethylcellulose (CMC-Na) solutions in the presence of sodium and calcium ions. The solutions of various concentrations were prepared by solubilization in aqueous solutions of NaCl or CaCl2. The effect of monovalent and bivalent ions on apparent viscosity and viscoelastic properties of these solutions was studied. It was found that in the case of low concentrations of CMC-Na in the sample (up to 0.5% w/w) the elastic character increases. At the same time the stiffness of the sample is higher with higher concentration of calcium ion in the solution. This increase might indicate the formation of gel network. On the other hand the viscosity of these solutions decreases with higher concentration of calcium ions. In case of solutions with concentration higher than 1.5% w/w changes of viscosity did not happen by influence of addition ions. Rheological behavior was compared also with solutions prepared without adding an electrolyte as well as with acid form of carboxymethylcellulose (CMC-H). In terms of second part the molecular dynamic simulations of hyaluronan tetramer both sodium and calcium in aqueous medium were performed. Structure and arrangement of water molecules in the surrounding of hyaluronan chain were studied. Structure was described by formalism of radial distribution functions. In the case of system containing sodium ions only, the obtained results are in accordance with earlier published data. Presence of calcium ions does not cause qualitative changes during the radial distribution functions in comparison with the system with sodium ions.
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Molecular simulation study of aqueous solutions of alifatic alcohols
Peštuka, Martin ; Žídek, Jan (referee) ; Janeček, Jiří (advisor)
The aim of this bachelor thesis was to carry out set of molecular dynamic simulations of aqueous solutions of aliphatic alcohols in infinite attenuation. In order to work with molecular dynamic simulations it was necessary to become familiar with the program equipment to perform molecular dynamic simulations and analyze the results. Within the work the basic simulation boxes contained 300, 400, 500 and 1000 water molecules and one molecule of aliphatic alcohol. From the simulated trajectories we evaluated the volume change associated with the insertion of one particle of alcohol and the radial distribution functions around the molecule of solute. The results were compared with experimental data.
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